Circuit interrupting device for motor vehicle directional signal



June 26, 1962 K. BOHMER CIRCUIT INTERRUPTING DEVICE FOR MOTOR VEHICLEDIRECTIONAL SIGNAL Filed Oct 1?. 1960 IN VEN TOR. KARL BOHMER ATTORNEYUnited States Patent M 3,041,425 CIRCUIT INTERRUPTING DEVICE FDR MOTORVEHICLE DIRECTIONAL SIGNAL Karl Bohrner, 1987 Balfour, Sandwich East,Windsor, Ontario, Canada Filed Oct. 17, 1960, Ser. No. 63,010 1 Claim.(Cl. 200-113) This invention relates to circuit breakers or interruptersgoing through a repeating cycle automatically and adapted particularly,but not exclusively, for use in directional signal systems for motorvehicles.

One of the objects of the present invention is to provide an improvedcircuit breaker or flasher for motor vehicles whereby a number ofserious disadvantages of prior de vices of this general nature have beenovercome and largely eliminated without introducing new problems orincreasing appreciably the costs involved.

Another object of the invention is to produce an improved circuitinterrupter for directional signals of motor vehicles which includes aresistance wire adapted to be heated by passage of electric current andcooled after the current is interrupted or broken, and thus expandingand contracting repeatedly to exert a pulling force on the snapmechanism making and breaking the electric circuit at a pair of contactpoints.

A further object of the present invention is to provide an improvedcircuit breaker of the characterspecified in the preceding paragraph inwhich action of the circuit making and breaking mechanism is of asnapping nature, thus producing rapid separation of the contact pointsand reducing sparking thereat and also effecting movement of the movablecontact point over a relatively long distance, thus producing sufiicientseparation of the points and reliable action of the mechanism.

A still further object of the present invention is to provide a circuitbreaker of the nature specified above which is characterized by smoothaction, with no-shocks exerted on the resistance wire, thus eliminatinga highly objectionable condition resulting in stretching of theresistance wire and changing its calibration after a relatively shortperiod of operation. I l

A still further object of the present invention is to provide animproved circuit breaker of the above character which in spite of thesmoothness of its action, retains a clicking noise highly desirable indevices of this nature. Such clicking is not found in circuit breakersincluding magnetic coils.

A still further object of the present invention is to provide a circuitbreaker of the above nature having a very strong snap action.

It is a still further object of the present invention to provide acircuit breaker of the above character including means operating aseparate set of contact points controlling a pilot light on theinstrument panel of a motor vehicle. b 7

It is an added object of the present invention to provide an improvedcircuit breaker of the automatically repeating type, particularlyadvantageous for use in motor vehicles for directional signals thereof,which breaker is simple and rugged in construction, dependableoperation, does not require oversensitive calibration and is relativelyinexpensive to manufacture. Y Further objects and advantages of thisinvention will be apparent from the following description and appendedclaim, reference being had to the accompanying drawings forming a partof this specification, wherein like reference characters designatecorresponding parts in the several views.

FIG. 1 is a perspective View showing an improved circuit interruptingdevice embodying the present invention, with a cover on.

I scription and not of limitation.

3,041,425 Patented June 26, 1962 FIG. 2 is an elevational view of thedevice with the cover removed but indicated in place in phantom lines.The front portion of the base plate carrying the front prong is removedfor clarity of the drawing. The parts of the device are shown in anormal or cold position of the resistance wire and with the contactpoints open.

FIG. 3 is a view similar in part to FIG. 2 but showing the parts of thedevice with the contact points closed.

FIG. 4 is a perspective view illustrating the snapper spring separately.

FIG. 5 illustrates the L-shaped bracket separately.

FIG. 6 illustrates the T-shaped standard separately.

FIG. 7 is an elevational view taken on the snapper spring, the observerbeing presumed to look from right to left in FIG. 2.

FIG. 8 is a perspective view showing a modified construction of theL-shaped bracket and the T-shaped standard combined in said constructioninto one piece.

It is to be understood that the invention is not limited in itsapplication to the details of construction and ar rangement of partsillustrated in the accompanying drawings, since the invention is capableof other embodiments and of being practiced or carried out in variousways. Also, it is to be understood that the phraseology and terminologyemployed herein is for the purpose of de- Particularly, it will beunderstood that the terms lower and upper as used in the specificationand the claims relate to the position of the device as shown in thedrawing, and are used for convenience of description; should theposition of the device be changed such as by turning it upside down fromthe position shown in the drawing, the respective terms would have to bechanged correspondingly. It will also be understood that the deviceillustrated herein may be used in any position without affecting itsoperation.

' In the drawing there is shown, by way of example, a circuit breakerembodying the present invention. Referring particularly to FIGS. 1-7,the device illustrated therein comprises a round base plate 10 made ofan insulated material such as fiber. On said base plate 10 there isoperatively mounted the circuit mechanism described below. A cup-shapedcover 11 covering the breaker mechanism may be made of any suitablematerial, such as sheet aluminum. Prongs adapted for inserting thedevice into a suitable plug for connecting it to the circuit areprovided on the bottom surface of the plate 10. I

The mechanism comprises an L-shaped bracket generally designated by thenumeral 15 and shown separately in FIG. 5. The bracket 15 includes avertical bar 16, a horizontal bar 17, and a downwardly protruding bar 18forming one of the prongs. The central portion of the horizontal bar 17is pressed out as shown at 19 to provide a bifurcated end 1941 adaptedto receive for anchoring therein one end of the thermal wire generallydesignated by the numeral 20. The bracket 15 is secured to the baseplate 10 with the aid of a rivet 21. The upper end of the bar 16 of thebracket 15 is reduced in its width as indicated at 22 and its upperextremity is bent to provide a hook 23 for the purposes explained below.

With the bracket 15 there is operatively associated a T- shaped standardgenerally designated by the numeral 25 and shown separately in FIG. 6.The standard 25 has its knife edge 26 resting in a groove 27 provided atthe juncture of the vertical bar 16 and horizontal bar 17 of theL-shaped bracket 15, see FIG. 2. The substantially horizontal barprovided in the upper end of the standard 25 is formed by punching outmaterial of its upper portion to form a hook 28 for the purposesexplained below and a bifurcated end 29 adapted to receive the end ofthe stretched portion of the resistance wire 20 retained therein in anysuitable manner such as with the aid of suitable beads. For the purposesof better retention of said end the portion 29 is made inclined.

A snapper spring generally designated by the numeral 35 is shownseparately in FIG. 4. It is in the form of an elongated resilient stripmade of hard copper or other suitable material.

An elongated central opening 36 is cut out in the body of the resilientstrip in such a manner as to extend over 'a substantial portion of itslength and to form a tongue 37 extending from the lower end of theopening 36 toward its upper end but to terminate short of reaching thesame and thus provide a free end 372. The tongue 37 is slightly pre-bentto ensure that pressing downwardly on its end 37c would cause furtherbending thereof. The lower end of the strip 35 carries two contactpoints 38 and a strip 39 with a contact point 39a for the purposesexplained further below.

The snapper spring 35 is suspended on the hooks 28 and 23, asillustrated. It is important to appreciate that the distance designatedby the letter d in FIG. 2, which is the distance between the surfaces ofthe hooks 23 and 23 contracted by the snapper spring 35, is smaller thanthe distance designated by the letter D in FIG. 4, which is the distancebetween the surfaces on the snapper spring 35 contacting the hooks 28and 23, in the free position of said snapper spring 35. Therefore,mounting the snapper spring 35 on said hooks 28 and 23 causes the tongue37 to be bent as illustrated in FIGS. 2 and 3, and, therefore, to exertupward force on the hook 23, in consequence whereof the top portion 35eof the snapper spring 35 exerts downward force on the hook 28, thusretaining the snapper spring 35 in place resiliently. In such acondition the contact point-carrying end of the snapper spring 35 comesto a certain position of balance. An angle bracket 40 having itshorizontally extending portion riveted to the base plate together withthe prong 41, with the aid of a rivet 42, carries on its vertical legtwo contact points 43 cooperating with the contact points 38.

The thermal wire 20 having its lower end anchored at 19a, has the upperend of its strung portion 20a anchored in the end 29 of the standard" 25in a suitable manner, as mentioned. The remaining portion 20b of thewire 20 is coiled, as illustrated, with the lower end of said coiledportion being connected in any suitable manner to the bracket 40 toprovide an electrical contact therewith. The portion 20;: of the. wire20 is tightly strung between the ends 19 and 29, as mentioned.

It will now be seen, in view of the foregoing, that the snapper spring35 tends, when it is in its mounted position, to keep the upper end ofthe standard 25 in a certain position. With the Wire 20 being cold andin its strung condition, the contact points 38 and 43 are separated. Itis this position that is illustrated in FIG. 2, wherein a clearancespace 45 between the leg 16 of the bracket and the standard 25 is at itsmaximum.

Should there be electric current circulating in the circuit to which theprongs 1S and 41 are connected, the electric current will flow onlythrough the resistance or thermal wire 20. Because of the highresistance characteristics of said wire, the same will become heated andexpand, causing sufficient elongation of the strung portion a of thewire 24 to permit the end 29 of the standard 25 to move to the right.Such movement of the end 29 will cause snap movement of the snapperspring 35, with its contact points 38 contacting contact points 43 andthus providing a parallel circuit through the snapper spring 35. Such acondition of the mechanism is shown in FIG. 3. Under such condition,with the resistance of the parallel circuit completed by the snapperspring being incomparably smaller than that of the resistance wire 20,most of the current will flow through said parallel circuit, thusdecreasing the flow of the circuit through the resistance wire 20 to thepoint when no heating thereof takes place.

'As a result, the Wire 20 cools rapidly, contracts, and are erts astrong pulling force on the end 29 of the standard vehicle.

25 moving it, in opposition to the mechanism action of the snapperspring 35, to the left. As such movement of the end 29 and of the topportion 352 of the snapper spring 35 continues, a point is reached whenthe lower end of the snapper spring 35 moves to the left with a snap,breaking the contact between the points 38 and 43 and thus opening thelow resistance circuit. Thereupon, the current again flows through thewire 20 heating the same and repeating the cycle. Such operation of thedevice will continue as long as there is current in the circuit to whichthe prongs 18 and 41 are connected. It will be understood that theposition of the lower end of the snapper spring 35 with .the wire 20being cold may be experimentally determined, whereupon the position ofthe bracket 40 is thus located to have the contact points 38 and 43closed when the wire 20 is hot, thus providing for the operationdescribed above.

In order to ensure that the snapper spring 35 is retained in place onhooks 28 and 23, grooves 28g and 23g are provided on the hooks 28 and23, respectively, as is best shown in FIGS. 5 and 6.

As mentioned above, the snapper spring 35 and the bracket 40 areprovided with two sets of contact points, thus ensuring doublecontacting, making contact more reliable and decreasing the sparkingbetween the contact points at the moment of separation, since breakingthe contact will occur at the pair of contact points separating last.

In order to ensure that both sets of contact points come into fullcontact, raised spots 44 and 45 are provided on the snapper spring 35,as illustrated, thus enabling said snapper spring to adjust itself byslight axial rotation at the time of contacting to form a perfectcontact at bothsets of contact points. It will be understood, however,that the invention is fully applicable with the use of a single ratherthan a double set of contact points. It will also be noted that forcesexerted on the snapper spring 35 by the hooks 28 and 23 act along astraight line preventing the snapper from moving sidewise. 7

It is desired that a separate circuit controlled by the device beprovided for operating the pilot on theinstrument panel of the motorvehicle, which light reproduces flashing of the signal lights providedon the front and back of the vehicle. ,In accordance with the invention,this is attained by the provision of the strip 39 secured to the lowerend of the snapper spring 35 and carrying a contact point 39a adapted tocooperate with the contact point 46 provided on the bracket 47 mountedon the plate 10 and electrically connected with a third prong 48 withthe aid of a rivet 49 holding the bracket 47 and the prong 48 to thebase plate 10.

The arm 39 and its contact point 391; may be eliminated. In such a casethe bracket corresponding'to the bracket 47 is placed along side thebracket 40 but electrically separated therefrom for the reasons ofWiring in the motor Then the two points on the snapper spring 35 wouldcontact two contact points on separate brackets 40 and 47. The snapperspring may then be made wider, if desired.

It may also be desirable to extend the horizontal leg of the bracket 40under the horizontal leg 17 of the L-shaped bracket 15 for connection tothe plate 10 with the rivet 21. However, suitable insulation is providedto insulate the horizontal leg of the bracket 40 from said rivet 21 aswell as the bracket 15. V

FIG. 8 illustrates a modified construction in which the L-shaped bracket15 and the standard 25 of the construction of FIGS. l-7 are combinedinto a single physical member as illustrated. in said FIG. 8. Referringto said figure, an articulated spring bracket shown therein includes ahorizontal bar 50 having a projection 51 corresponding to the projection19 and adapted to receive the end of the wire 20 for anchoring. Theprong 52 receives for anchoring the other end of the strong portion 21of the wire 20. Portion 53 serves as the upper hook. The bent end 54 ofthe tongue 55 serves as the lower hook. A snapper spring 35 is mountedon the hook portions 53 and 54. Movement of the tongue 55 with respectto the vertical bar 56 of the bracket is attained by bending the bridgeportion 57 at the bottom of the tongue. A separate prong serving thesame function as the prong portion 18 is connected to the plate 10 by arivet which passes through the hole 58 and thus holds the bracket to theplate 10. In other respects, the construction and operation of thedevice including such spring bracket is similar to those of theconstruction of FIGS. 1-7.

There is thus provided an improved circuit breaker of the automaticallyrepeating cycle type, whereby the object of the invention listed aboveand numerous additional objects and advantages are attained.

I claim:

In a circuit breaking device, a base plate, a bracket forming oneterminal, a stationary contact point provided on said bracket, a secondbracket of an L shape with the horizontal bar of the L being secured tothe base plate and the vertical bar of the L extending upwardly andhaving its end bent to form a hook, a T-s'haped standard associated withsaid L-shaped bracket and arranged thereon to have its vertical barparallel to the vertical bar of said bracket and the horizontal bar ofthe T forming two hooks, an elongated resilient strip including twoportions having their lower ends connected and carrying a movablecontact point and their upper ends free, said strip being suspended onone hook of said T-shaped standard by the free end of one of saidportions, with the hook of said L- shaped bracket bearing down on theend of the other portion of the resilient strip to put said portion inbending, a resistance wire strung between the other hook of the T-shaped standard and the end of the horizontal bar of the L-shapedbracket to exert pulling force thereon and to move it transverselytoward said end and thus to move the point-carrying end of said stripaway from the stationary contact, said resistance wire being adapted,when heated by passage of electric current therethrough to expand and torelease said pulling force in order to cause the top of the T-shapedstandard to move to the side of the permanent contact and thus to causethe contact-carrying point of said resilient strip to snap move towardthe stationary contact and thus to close the circuit and thus to reducethe current flowing through said wire and to cause its cooling forre-asserting said pulling force and repeating the cycle.

References Cited in the file of this patent UNITED STATES PATENTS2,242,769 Werner May 20, 1941 2,486,033 Kaminky Oct. 25, 1949 2,689,283Pulva-ri Sept. 14, 1954 2,820,120 Flatt et a1. Jan. 14, 1958

